Toxic chemicals have been accumulating in various waste sites as well as in other industrial, urban and rural areas throughout the United States. In this project, we plan to study basic mechanisms and toxicological meaning of microbial and photochemical degradation technologies to promote on-site (in situ) degradation of toxic wastes. We plan to utilize Phanerochaete chrysosporium, a well-studied white rot fungi, as well as several Trichoderma spp. which are known to offer a wide variety of degradative capabilities. To study the basic mechanisms of microbial degradation we plan to assess the relationships between the levels of ligninases (H2 and H8) and manganese peroxidase vs. degradative ability of the fungus on toxic chemicals. An effort will be made to study their metabolic systems to explain the fundamental mechanisms as well as toxicological significance of their metabolic alteration. Ultimately these efforts should result in maximization of degradation abilities of these organisms. At the same time, we plan to combine the above microbial technology with photochemical degradation technology. The P. chrysosporium method is particularly suited for this combined approach, since they are the most ultraviolet resistant species among all white-rot fungi we tested, and since they generated H2O2 which promotes photochemical degradation of organic chemicals. Furthermore, they grow well at liquid surfaces where oxygen tension is high and UV light can easily reach. Photochemical reactions will be first studied as a separate treatment and second combined with microbial actions. The basic cause(s) for synergism of these two technologies will be studied by determining their mechanisms and the nature of the products.